Doctoral Thesis Defense: Min Chen

Speaker: Min Chen

Supervisor: Dr. Y. Yang

Examining Committee: Drs. V. Haarslev, A. Hamou-Lhadj, N. Shiri,
W. Shen, C. Wang (Chair)

Title: QoS-Aware Service Composition and Redundant Service Removal

Date: Friday, February 6, 2015

Time: 14:00

Place: EV 1.162

ABSTRACT

Automatic Service Composition (ASC) is the generation of a business process to fulfill business goals that cannot be fulfilled by individual services. In addition to satisfying the functional goals, recent research is geared towards selecting the best services to optimize the QoS measures, such as throughput and response time, of the target business process.

In this thesis, we study QoS-aware service composition problem to satisfy the functional requirements and optimize the QoS at the same time. We are motivated to extend AI planning from the ASC solver into the QoS-aware service composition solver. It is because planning algorithms,e.g. the Graphplan technique, are frequently used for the generation of a business process to achieve functional goals. We propose two methods to combine the Graphplan with Dijkstra's algorithm to solve QoS-aware service composition problem. The experimental results demonstrate the feasibility of the proposed methods and compare the advantage and disadvantage of the two methods.

We also study redundant service removal problem to further optimize the QoS optimal solutions obtained by QoS-aware service composition algorithms. Fewer number of services indicates less execution cost to invoke these services. Even if execution cost is not explicitly given for each service, it is still beneficial to reduce the number of services in the final solution by assuming each service takes unit cost.